A great many medical procedures in use today involve the insertion of a medical device into a living body in order to pierce a wall of a blood vessel or other similar structure within the body. Examples of such devices include biopsy needles, laparoscopes, trochars, introducers and various other probes that may be inserted into the body. The surgical insertion of such devices creates a wound, which commonly passes through the wall of a blood vessel or other similar tubular structure within the body. When the medical device is withdrawn, an opening is left in the wall of the blood vessel or other tubular structure, which allows for the possibility of the contents of that tubular structure leaking out into the surrounding tissue. In particular, arterial punctures, that is punctures through the wall of an artery, offer the opportunity for significant bleeding because of the relatively high pressure of blood within the artery. Bleeding from a vessel puncture in a substantially sized blood vessel can be severe.
In performing these medical procedures, the medical device pierces the epidermis of the skin and continues to create an incisional tissue tract through tissues intervening between the epidermis and the vessel wall. Finally, the medical device pierces the vessel wall creating a vessel puncture. Typically, a tubular structure holds the tissue tract open to allow for the repeated introduction of instruments into the body during a medical procedure associated with the creation of the vessel puncture. Depending on the context this tubular structure goes by many names, but will be referred to for purposes of this invention as an introducer.
Because vascular access procedures are so common and because the potential complications from failing to effectively seal a vessel puncture can be severe, substantial efforts have been made to resolve the problem of plugging or sealing vessel wall punctures. A variety of different approaches have been used in the art.
One approach is to insert a flat plug on the end of a filament into the blood vessel lumen and to then withdraw the filament in order to pull the plug until it is flush against the interior blood vessel wall. The filament is generally secured to the center of the flat plug. The plug and filament may be made of a biodegradble material that will gradually be absorbed by the surrounding tissue. Once the plug is in place, the filament is tensioned and then secured, typically to the skin on the outside of the body. Examples of this approach include U.S. Pat. Nos. 4,744,364; 4,852,568; 5,021,059; 5,222,974; 5,507,744; 5,643,317; 5,601,602; 5,620,461; 5,676,689; 5,746,755; 5,916,236; 5,947,997 and 6,045,569. Potential problems with this approach are that the point of anchorage may be dislodged or that the filament leading to the outside of the body will provide a continuing path for pathogens creating the possibility of infection. The physician must affirmatively act to fix the device in place. The requirement that the filament be secured to the body exterior adds an additional time-consuming step to the procedure. Tension must be maintained on the filament until it is secured.
Another approach to sealing vessel wall openings is to use cautery via heat radio frequency energy or electrical energy. Examples of this approach include U.S. Pat. Nos. 5,810,810 and 6,063,085. While mostly effective, this approach typically requires more complex and expensive equipment and the success rate is dependent upon the skill of the operator of the equipment.
Several approaches to sealing vessel punctures involve the insertion of material into the tissue tract or vessel. Examples of injecting or inserting a clotting induction agent such as collagen that encourages clotting at the puncture site are shown in U.S. Pat. Nos. 5,591,205; 5,601,602; 6,090,130; 6,162,192; and 6,334,865. Another approach is to place an expanding haemostatic material in the tissue tract outside of the wall of the blood vessel that has been punctured. For example, Gel Foam may be inserted at the location of the juncture of the tissue tract and the vessel wall puncture. Examples in the art taking this approach include U.S. Pat. Nos. 5,108,421; 5,324,306; 5,649,959; and 6,179,863. The challenge with these approaches is preventing the clotting induction agent or expanding hemostatic material from being introduced into the blood vessel itself. The introduction of either agent into the general blood circulation may lead to emboli which will travel with the circulating blood and may lodge in smaller blood vessels leading to interruption of blood flow and ischemia in a remote location. Ischemia can lead to serious consequences.
Yet another approach to closing the vessel puncture is that of inserting a collapsed expansible plug into the blood vessel lumen and then expanding the plug once it is in place. Examples of this approach include U.S. Pat. Nos. 5,350,399; 5,454,833; 5,782,860; 5,922,009 and 5,951,589. These disclosures generally envision an umbrella-like structure that is passed down the tissue tract until it is fully within the vessel lumen. Once within the lumen, the umbrella-like structure is opened and then the portion equivalent to the umbrella handle is withdrawn into the tissue tract in a closed position until the opened canopy structure is snugly against the vessel wall. The entire structure is then secured in place. The umbrella-like structures utilized are rather bulky even in the closed state. This requires that the tissue tract be enlarged beyond what may be necessary for accomplishing the primary medical procedure in order to accommodate the umbrella-like structure. Further, the act of deploying the umbrella-like structure in the vessel lumen may be disadvantageous, particularly as the umbrella-like structure may disrupt the fluid flow within the vessel and thereby encourage thrombus formation.
Lastly, there is an approach to sealing the vessel wall puncture utilizing a small balloon inserted through the tissue tract to block the vessel puncture sited. An example of this approach can be found in U.S. Pat. No. 5,716,375. The balloon is inserted in a deflated state, positioned and then inflated to seal the passage. The challenge with this approach is controlling what happens to the balloon after the puncture is sealed and, like the flat plug embodiments, keeping the balloon secure against the vessel wall while the puncture heals.
The medical arts would benefit from a device that allows for the sealing of blood vessel wall punctures that are created at the termination of a tissue tract that passes through intervening tissues between the vessel wall puncture and a puncture through the skin. It would be preferred if the device was self-securing and small in size so as to be introduced without the need to enlarge the tissue tract beyond the size needed to perform the primary medical procedure.